Because the radio propagation environment is adverse, signals transmitted by a Base Station (BS) in a wireless communication network are usually reflected, scattered, and refracted repeatedly before arriving at the receiver of a Mobile Station (MS), which tends to cause multi-path fading of signals. In a fading environment, multi-antenna diversity technology can improve the performance of the wireless communication system effectively.
Closed Loop Transmit Diversity (CLTD) and Multiple Input Multiple Output (MIMO) are examples of the multi-antenna diversity technology.
In CLTD mode, it is assumed that the uplink (UL) CLTD is the same as the downlink (DL) CLTD except for different transmission channels. In UL CLTD mode, a User Equipment (UE) combines signals of several channels and then scrambles the signals. The signals are transmitted through two or more antennas after the signals on each antenna are multiplied by a weight value. The weight values are w1=1/√{square root over (2)} and
      w    2    ∈            {                                    1            +            j                    2                ,                              1            -            j                    2                ,                                            -              1                        +            j                    2                ,                                            -              1                        -            j                    2                    }        .  The value of w2 depends on the downlink Precoding Control Indication (PCI) information.
The BS (such as a NodeB) calculates the weighted sum of signals of two data streams after receiving the signals of the two data streams. The weight values are w1 and w2 used by the UE at the time of transmitting the signals.
In the process of implementing the present invention, the inventor of the present invention finds at least the following problems in the prior art: In a macro diversity state, the signals transmitted by the UE are received by multiple cells simultaneously, and are soft-combined; the two received data streams cannot be combined correctly unless the NodeB of non-serving cells also obtains the PCI information in time; but non-serving cells are unable to obtain the PCI information in time currently. The MIMO mode is also baffled by this problem.